<!DOCTYPE html>

<html lang="en">

<head>

	<meta charset="UTF-8">
	<meta http-equiv="X-UA-Compatible" content="IE=edge">
	<meta name="viewport" content="width=device-width, initial-scale=1.0">
	<title>注册页面</title>
</head>

<body style="margin: 50px;">
	<table border="1" width="1000">
		<tr style="background-color: #999;">
			<th><input type="checkbox"></th>
			<th>分类ID</th>
			<th>分类名称</th>
			<th>分类描述</th>
			<th>操作</th>
		</tr>
		<tr>
			<td align="center"><input type="checkbox" name="chekbox"></td>
			<td>1</td>
			<td>手机数码</td>
			<td>手机数码类商品</td>
			<td><a href="">修改</a>|<a href="">删除</a></td>
		</tr>
		<tr>
			<td align="center"><input type="checkbox" name="chekbox"></td>
			<td>2</td>
			<td>电脑办公</td>
			<td>电脑办公类商品</td>
			<td><a href="">修改</a>|<a href="">删除</a></td>
		</tr>
		<tr>
			<td align="center"><input type="checkbox" name="chekbox"></td>
			<td>3</td>
			<td>鞋靴箱包</td>
			<td>鞋靴箱包类商品</td>
			<td><a href="">修改</a>|<a href="">删除</a></td>
		</tr>
		<tr>
			<td align="center"><input type="checkbox" name="chekbox"></td>
			<td>4</td>
			<td>家居饰品</td>
			<td>家居饰品类商品</td>
			<td><a href="">修改</a>|<a href="">删除</a></td>
		</tr>
	</table>
	<script>
		let arrTr = document.getElementsByTagName("tr");
		for (let i = 1; i < arrTr.length; i++) {
			let objTr = arrTr[i];
			if (i % 2 === 0) {
				objTr.style.backgroundColor = "blue";
			} else {
				objTr.style.backgroundColor = "white";
			}
		}


	</script>



</body>

</html>